Method of forming o-ring grooves

ABSTRACT

A method of forming O-ring grooves in a tube; inserting an end of the tube within a die and pulling or pushing a plunger against a cylindrical resilient member, forcing the resilient member to exert a pressure against the walls of the tube, thereby forcing the tube against the die surfaces.

United States Patent William K. Fanning Morton:

Vincent R. I-lodel. Roanoke, both of, III. 800,575

Feb. 19, 1969 July 27, 197 1 Caterpillar Tractor Co.

Peoria, 111.

Inventors Appl. No. Filed Patented Assignee METHOD OF FORMING O-RING GROOVES 5 Claims, 2 Drawing Figs.

29/523, 72/370 Int. Cl BZld 13/06 Field of Search 72/54, 57,

[56] References Cited UNITED STATES PATENTS 2,417,202 3/1947 Hull et a1. 72/62 2,458,854 1/1949 Hu" et a1. 72/58 2,704,104 3/1955 Mueller 72/58 FOREIGN PATENTS 639,103 6/1950 Great Britain 72/62' Primary Examiner-Richard J. Herbst Altarney--Fryer, Tjensvold, Feix, Phillips & Lempio ABSTRACT: A method of forming O-ring grooves in a tube; inserting an end of the tube within a die and pulling or pushing a plunger against a cylindrical resilient member, forcing the resilient member to exert a pressure against the walls of the tube, thereby forcing the tube against the die surfaces.

PATENTEDJUL27I9?! 3,595,047

INVENTOR S WILLIAM K. FANNING VINCENT Hi, HODEL BY '7: w w, m 747% METHOD OF FORMING O-RING GROOVES BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to the formation of O-ring grooves in tubing.

In the conventional methods of manufacturing O-ring I grooves, such as the machining of connectors which are then brazed to tubes, two-step die upsetting, and similar methods, problems have long been encountered in the high cost of manufacture, waste of material, and addition of unnecessary weight to the product.

The method disclosed in this application is preferred over any of the known methods since only one operation is required and the groove may be formed out on the tube wall without adding extra material to the product.

Therefore it is an object of this invention to provide a method of forming O-ring grooves on tubing.

It is also an object of this invention to provide such a method which greatly reduces the cost of forming such grooves.

It is a further object of this invention to disclose such a method in which the parts utilized to form the grooves are reusable.

Other objects and advantages of the present invention will become apparent from the following description and claims as illustrated in the accompanying drawing which, by way of illustration, shows a preferred embodiment of the present inverition and principles thereof and what is now considered to be the best mode contemplated for applying these principles. It is recognized that other embodiments of the invention utilizing the same or equivalent principles may be used, and structural changes may be made as desired by those skilled in the art, without departing from the present invention and purview of the appended claims.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a sectional view of an embodiment of apparatus which may be utilized to form the O-ring grooves according to the method of the present invention, with the parts in position prior to formation of the groove; and

FIG. 2 is a view similar to FIG. 1 with the parts in position upon completion of formation of the groove.

DETAILED DESCRIPTION OF THE DRAWING As shown in HO. 1, a tube is inserted into a pair of identical split dies 12 and 14 until it abuts against a stop 18 in a collar 20 which is immediately adjacent the split dies.

A hollow, cylindrically shaped slug of resilient material 21, having an outside diameter approximately equal to the inside diameter of the tube and an inside diameter approximately equal to the inside diameter of the collar 20, is placed in the tube and within the die as shown.

The resilient member 21 may be manufactured from urethane or any suitable resilient material. It is preferred that the material utilized be able to regain its original shape upon completion of the method described herein. This will allow the cylindrical member to be reused, providing greater economy.

With the two halves of the split die 12 and 14 secured so as to prevent their separation, hydraulic pressure is applied to a plunger 22 extending through the member 21 so as to cause the head 24 of the plunger to compress the resilient material. Since the resilient material is confined between the tube and the collar, the hydraulic pressure causes the thin wall of the tubing to yield and take the shape of the inside diameter of the die cavity 26.

If desired, a solid, cylindrically shaped resilient member could be used and the hydraulic force may be applied to a piston, which replaces head 24, so that the plunger shank would not be needed.

Although only one embodiment ofa machine which may be utilized to practice the present invention has been disclosed, it Will be obvious to those skilled in the art that a great number of machines can be utilized to practice the invention, without exceeding the purview of the following claims.

What we claim is:

1. A method of simultaneously grooving and flaring out the end of a tube to a diameter which is greater than its diameter prior to forming which is accomplished from within comprising the steps of placing the tube within a die such that the tube end is radially adjacent one of a plurality of spaced circumferential grooves in said die, placing a resilient member within the tube and confiningthe resilient member within the tube and exerting a force on the resilient member in a direction coincident with the tube axis, thereby causing said resilient member to expand radially and deform the tube into each of said grooves whereby forming of O-ring grooves in the tube wall and flaring of the tube end to a diameter which is greater than its diameter prior to forming occurs simultaneously.

2. The method of claim 1 including the step of abutting one end of the tube against a stop adjacent one end of the die when placing the tube within the die.

3. The method of claim 2 including the step of positioning a plunger head in the tube and adjacent the resilient member and moving the plunger head against the resilient member to exert the force thereon.

4. The method ofclaim 2 including the steps of positioning a plunger so as to extend through an aperture in the resilient member, thereby positioning a plunger head against the resilient material, and drawing upon the plunger so that its head moves against the resilient member to exert the force thereon.

5. The method of claim 1 including the steps of abutting the tube and the resilient member against a collar situated at one end of the die, and drawing a plunger through the resilient material and the collar so as to accomplish the step ofexerting a force on the resilient member by confining the resilient member between a head on the plunger, the collar, and the die cavity and decreasing the distance between the plunger head and the collar.

323? UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,595,0 4? Dated July 27, 97

Inventor(s) WILT-TAM K. FANNING, et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 1, line 6, after "die", insert --and the tube wall is radially adjacent a second one of a plurality of spaced circumferential grooves in said die-.

Signed and sealed this 1 8th day of January 1 972.

(SEAL) Atte st:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Acting Commissioner of Patents 

1. A method of simultaneously grooving and flaring out the end of a tube to a diameter which is greater than its diameter prior to forming which is accomplished from within comprising the steps of placing the tube within a die such that the tube end is radially adjacent one of a plurality of spaced circumferential grooves in said die, placing a resilient member within the tube and confining the resilient member within the tube and exerting a force on the resilient member in a direction coincident with the tube axis, thereby causing said resilient member to expand radially and deform the tube into each of said grooves whereby forming of O-ring grooves in the tube wall and flaring of the tube end to a diameter which is greater than its diameter prior to forming occurs simultaneously.
 2. The method of claim 1 including the step of abutting one end of the tube against a stop adjacent one end of the die when placing the tube within the die.
 3. The method of claim 2 including the step of positioning a plunger head in the tube and adjacent the resilient member and moving the plunger head against the resilient member to exert the force thereon.
 4. The method of claim 2 including the steps of positioning a plunger so as to extend through an aperture in the resilient member, thereby positioning a plunger head against the resilient material, and drawing upon the plunger so that its head moves against the resilient member to exert the force thereon.
 5. The method of claim 1 including the steps of abutting the tube and the resilient member against a collar situated at one end of the die, and drawing a plunger through the resilient material and the collar so as to accomplish the step of exerting a force on the resilient member by confining the resilient member between a head on the plunger, the collar, and the die cavity and decreasing the distance between the plunger head and the collar. 